SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a41f4932b517a02bfcf771f4c41ebde766cde736656bda4ed9850832d4f6e539' 
  AND token = 'Gz/yWdifgKA2Y5MdmJvvBoqeIY0FLskreJbLDO09EeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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