SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'daca3f8226f7f04e86285cf20261d7720decdead5c7826d6347f15806bcca5ae' 
  AND token = 'AcoM/xvppzlWjxgHTDbal/xN8lSIglD2fWjXjhQIjmo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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