SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77d0a2c38043f8531b0f4aa65af1ea8e372b116a426dc475a213248ac7c7b814' 
  AND token = 's9MkSkT++2l2O9/daDznJ4KqUY3prqfVv9tvPIzZ6WA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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