SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c53111059e9cdfc13d83ad597d0179d1afff6e22074e7b5c827132d941253adb' 
  AND token = 'ndtmgZXI9jGcjih+zYIJQ/jnEg84AJ+cXmSnzJ/K4sE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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