SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30ede596da913f1c552f1c303f3576b7fea497689f342e8d2df5ed32b5788bdf' 
  AND token = 'wYV6pF+fwErD+UPEzFrsEcUjw0EC/z+gX8B/i1RDNWA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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