SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b13480861e7486eb785cbcb6663e33e250bf0d40140ef0a41fee5310af2ddad' 
  AND token = 'iLasO6jY6699UTle0GF0iKOUVFfEib3OIHWElCIcyD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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