SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '363615407d9194e3ea397f0f010b869643aa29a737eacd66d692ec6c303dd3e3' 
  AND token = 'lhNEzpcQtCGqNxbtvn6VhX9ozoG6VBys12+jE4o5NTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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