SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '226a988bad977dcb8c4a741cf16184af2a7e5cb645675f93e629d117b454be32' 
  AND token = 'BxSwSPcSiXpmJCHJNJbypvmbRq9YMKf2Fr77XWI81Bc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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