SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d9efdfb25c11b80893939334cb36fd29d346e19420c21a8b61a027bf7f1e1b3' 
  AND token = 'JWUhkx6BQPYOPrFx+CA4WK+jsvMGFLWHlegsvQ9RPAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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