SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '365a8df527f01bebd77f892b2fd083e914cd4569c25ea48fff68f6eba846e935' 
  AND token = 'QBYliCRUkV4bJMBqG/uIK84yTBqi6LAqQbOePIapZSo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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