SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe9d7270975e42792817570e837ef9ca0d1cb8225f1c26774e7f6ac6531c059d' 
  AND token = '8OEQk0RTCjITG5kJj1lW8EpEB8w+jj8o7jv4WRYPdg4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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