SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b23a7862626f056f36afa00b97f956aff470f79bb6dcc33b508a33b9bf8fb9fd' 
  AND token = 'aB3UbIc0t38CWtW/QxxfV1sU7mS9fja+vpyW7uKwfUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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