SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3aff06257a882e6744bf542e7b143fd789b7db920640e77c9c5f175ab7c0deff' 
  AND token = 'iku8JUWGingD1HtCJ4nQNkK29HafL1id79e0RfXu5FM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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