SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '411f30c5ac22dac3321cd748da9dca36e1e5350bc6135042b2fe4c70ba53fe17' 
  AND token = 'KhLn0cMjYLnm5U97/71WuVNz5QT4++5sHnRXSucMsAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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