SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '45793c537f982d65ad63c7ec0002a4a199de4ed3258fabac8c407ef77a5559cb' 
  AND token = 'LLVYgiBUPK8D2hZqlFfUBKW0PV4ows2eGH8k+xxBDRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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