SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a27b26b5421824ea18789cad8ad63763364d92d346707949bea80244d8138dc' 
  AND token = 'sDslA2VRp9yo3jAi2rAn45VmyJprOZn+GkSkZpLbh40=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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