SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f249672565d93f603c466b6d7eb52211eb05c9c0c4a73a345983528cef06b2b' 
  AND token = 'tV5pHc61F2wGMJXY3WJFzMTg1ytzpyJejRyRr9ltBuQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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