SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9b0bb577219d46199e7e4a7172af93846b2d3f6d1e457bf322a6d5584026cab' 
  AND token = 'SN7phXyZKmhG/yn6ruiBaszwK0GUSXEpl8d9hUGUAHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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