SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '457afc25a6fa4592e21b5cdefceac055c33b15c08f0554c661c25c08316a0665' 
  AND token = 'rCu1Cx7ER8CyleEI25WhcThcllkTC+cxmZWD3BtR3A8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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