SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af3fe7d7deceec8a8befe3522f3489897808bc498c1b5e0dabfd061ffd9bece7' 
  AND token = 'Byb+GyFpGmPLeVY4Sb+MbxWdQGrK6XjgA7054zn8ECE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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