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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a775bb2c6358836e3b8fda58e000a70c039bfa21f48d7397b43ea8929ec32471' 
  AND token = 'YCq4Ke+oHnp/6+uCDLAGfHf5HZ/oMLSEcbHIIaKpP7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}