SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59883c7e3cf47b0b98276d30c3ed1bb00b581808ea3a5ea69d232ec423a87667' 
  AND token = 'oWGrv6UpBKvhBIX1iF7+uJmFg7AHQHBm78B90HoZz4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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