SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '362ad42831b325337c771c8282a5f3c268cce7565bb27255db5a6dc33e059d4c' 
  AND token = 'pgetVztlJExzhMWh3bm8E3WGBM1vIRvrMskC5IeyT70=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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