SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a64a4721127fbf28c42ffccf676916550ffb76af4784932bd2486abe2f77b50e' 
  AND token = 'Zyen3Jvb1H8LRbGBlUCQdedOWJ54FtNgjUYjiaWG21I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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