SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09d40a90192f586c792775089cb763079c1dbb4bb183496f693b902841d665b0' 
  AND token = 'XQfEndybcY3yR2i0ZDUXt5hTgYYSPYlLApaWbV1gjvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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