SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9dffd9bfb21770116ce048f686b19b3ddb0d80001ae363f689867655685f30d' 
  AND token = 'IhBUtgGLIEW4wNBrEuUot1oZRJ5r4DwTpJLZe8AcoTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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