SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65aa8800a12efd8b36cb865183c270ebf6e0a55af6d15e8abfe858139d90d455' 
  AND token = '50ST8AAjT8aCpRMrE89mH1ZXDesZA3BBD8Ntzj0pJWU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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