SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5aa636248efb7f802f13a89727e9a9eb70acca27a1a9f35819530268de427aa7' 
  AND token = 'haVRGJ76gllyr330gPIZmbzY4Z+RshEy63NYMj6EQw0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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