SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1301724fb23c67628e58d30cb237b97def7360c062a5457a541b8ba47ed4a781' 
  AND token = 'LwLaxqVfsep8zQ40MHRYBwisZUwGxOlEByfsKQDiYaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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