SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '741f727e95cd446b2253a170ba55904f131a4f2906a3a537f8f98624aed68daf' 
  AND token = 'AMhE9qo3aliSilJrrDRPHEn4EPyWmafQt0aXGPWcCkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}