SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d49909e6e2bc14be0574bff0e41f4cd9916cb63b6c661a3139c6c1506c67414' 
  AND token = 'g0PwUgZ6Z72z0NStC7P3u+jPNha3n7iDKOwPA/tNiEo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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