SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82b603af0d7d1591c8c86acd3bf32d86903cd4c65a18b682d873379fb027257b' 
  AND token = 'wvPe0eLYXu+mvpbQbpO1cQOuBqW0J+7ayG/XqQ6FwGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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