SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5353b4e04a7b5029f81ed69fe9221a17b92df68d91113e30f77d787f8b7cc16c' 
  AND token = 'Dv1ZYzRhjBWgoyidix0zMz7e8OJwF6hHb4HQRTpXDdA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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