SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9fae9c2fc555b6987781c60a90fe3b42da00da2368f57ef1dba210b4c3603e9' 
  AND token = 'WYxg+UyJ+g6qGx2JnvPz+kHFSYRIocaJShC7R9Uwzpc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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