SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ddc1a35d1fb4d0d4971d9646dd2874200d54ab794d4192012e1f991fc196550' 
  AND token = 'MeoDHZeUwpqaFs/05xh+BvNI5HcDY5zIUKXwYVOUgUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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