SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '617d918db22238b3c14816c36fba0fbd8420aaed185a5b750282e9df303aac82' 
  AND token = 'H9oGI66rh44qQ1WG1hoPtv6x+dwf2Jxd1CvIZNH+kIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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