SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5903bdf46f10f704a3cba3d307a3e76b53eeb6c6ac5da508e71d16ab782eb91d' 
  AND token = 'HMSzvBSUlPMZHHmulsNCs0PMLxy3ydBWHoBYPYOdWt4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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