SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31ce65198029982365dfd57bbd0f275450922fedf78b36b522ea16b2d258ea62' 
  AND token = 'LginBv5AXNEDrMVRC5FGVADPRwvz/6J7Y3T3v9llqGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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