SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df60308eb0b416f1db2c2d9f3987fc84107c3af8eac569be2aa71a3c93b153c1' 
  AND token = 'zwJz9Gv7cwjhmTxyDZIJNPJOWIsCEm1XduCgblvsUiU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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