SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9a6c1bcc80e14278b7566bc2038ec2ee306ff5ac3a4ae26c858fe9f1511f3af9' 
  AND token = 'FNaIM6U1p+KulXrJAlFXjTVa4ZgPlXdyKeucCc6tyLA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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