SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a0f69a6ab7b3bb9d40d582352e06b9b7124b59ecaee5a052a42f1ae19b1fb2d' 
  AND token = 'VRNQamw9wzIpmVVzOxXuDcrQ0iaZMdsx6HDoHbprFwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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