SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a97cd89f5fe8b12d7fbd3bbb99fc84fb6a4e67772e53d9da71b50c270e4ca5d9' 
  AND token = 'oLAU9hi1hA+IvDyRxKZH/+s9jP53meEGaL1SWccdjn8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}