SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e1464e16eb13305a38d23380610dce2d33fb30932f1527cbe5e5059dae24e04' 
  AND token = 'PUBoGy+rakUdwCn8jXs+K/3iudZgz8jcMYC9MyfSsKg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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