SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c9d625a6861054767c09a126b88586e466cf98f876d37b117dd62aef28e3cc3' 
  AND token = 'hFKczhZoBQFDM6jgi1vOi2Jx0AExVK+jE3J6xA+Bqj4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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