SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f988144ad6c3a0845526efd9f76196784a98cb2448adae1d31e0b0b06bd400c' 
  AND token = 'nVoinlHl7VGDt5zjBeLZQx2dt8+2TV/6eygXVpQLnZY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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