SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '016d737a22d895e7b3c7b5dd3b2d68b749f93609b2476edbc5b5071eaf0e64ec' 
  AND token = 'k2C8qqinhBEJ7wigt+qoqyWm0JY+P7Wlu/aH0zIfQXw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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