SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd50d2c95d73af0cb52724ac38c0720c8fefc4f437fbf356f0e92f811aa44c84d' 
  AND token = 'K0ovbhYylP9p/HnBT1qpgNYWxODaYTyQeisNQfr6GGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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