SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '901eaeac07b9acd25d560925f706510b612184e3c497ec06bf364fc9253e700a' 
  AND token = '3SNWBdwTLeNUEeYOlgnkwLyL9iyKHMfWq84i76Yi4Iw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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