SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '792e58f0c79e2564e9661f0580a64d16513d403197b9753160160cad059613c0' 
  AND token = 'UaqTwHG6E3NOz2GPJqTAR3g88FV1LfQu7piZEeovDSM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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