SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3dc0eb26cef15161ac58e3094785dc8ff85cf6e1da47b656e4156e9fc0852293' 
  AND token = 'sJgOVDHig45kzFioFxkWnuQwhVZwH4aVJbRNyXdKmyw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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