SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b39b46c284e09bf5d31b147d2729ebc5c6fde36f73078f9c97a6c3ced3138b8' 
  AND token = 'nCoQfFW/HZa5VBWj2HbQtHA+QA/dvwjLyMO+PxK6l8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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