SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8181a3c88036726f33291431c61b75b4e2ff18b4ba08e5929954d8c4c52ff069' 
  AND token = '7tgWgS0vZXsF8Sn8BYf/Rt0Kg8XJT4aCrKj9IV8p+j0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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