SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63818bbc91f35314d18b1e5d87588ad797bbcb7da98e2770c21bb45865a1ecd8' 
  AND token = 'dzX3DKlKK6YOjUqQs7P15m9swuwlhaTjqgUmzrCKvZE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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