SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2826e41b13437bd9804cef28feeca27f9ba5713b5762706197e6773a01245af7' 
  AND token = 'uSn6nvKSOGuKQres6FTRTTFqjPsWBg0YljS98k4hVPA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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