SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f561689dcfb75ebc50b6a3238f18e2f84bfb449801003461891af9097a2a475' 
  AND token = 'KVGuc7J0Y76f/XTDGaq+UDgq0w2Szhjwcxq7DCfazfI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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