SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bd87d267f4fa9b66630c65b108eafd89fc36e4da9efbb38790e9f2d541792e4' 
  AND token = 'pHmDjUyLVs7w2CBTkRDJhhmg4NMRaLqezNEeWtEGHSk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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