SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f347e3dc2152fa9474bdf5ac7a41055c15b8015255ac7ce614c86fef187b587' 
  AND token = 'fnjY8laAiH+qKKDv6qOMaobmzJCO7Y/Y5QrmBugvYec=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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