SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '994e7d326420e59eb6320ff0b9c184599115bee5c92d5728bf2afcdbdcdeb782' 
  AND token = '1eWnD3MjteGglwowxgikqXuKItHU5b0vnVrzlNjXILs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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