SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57f8c869f3eacdf9474b7f1394aacecd33236f4b9f2031fb9a88b8b6308232e6' 
  AND token = 'm+0hETPwQ4zSSHABA8TPbuSqtyYzCcGN9GFkJoFvCJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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