SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f6ad0bbbb994bd2114e5d60c077f22d044ebba5b2b9e2a81ae054492d9421365' 
  AND token = 'jF0p7QsovDYF3Dj8kPzvzWeMrDFtkWtREoOFbKyHQBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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