SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9cf71403c7675d647b960bb70ded0289c4368da16f59534879dea1c274731c32' 
  AND token = '1t8wF98vlgFwQjq1hr8S+jk9bEnJM04RFDTCEBUGnL4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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