SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79136e6fd63ac00715603f8e215795be76e374251143b92c2945c24ad8eb483e' 
  AND token = '6ny2QdBMZnRsK2j3058tRoOHNFfT0kHOB/kDUpllz8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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