SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1ea4d135e429055c6d8f99cea489028eb84f2776747189ee91aec455eb5fa2e3' 
  AND token = 'hHmc29BhkT6nhotfSb1vRwMciDQwxPjfwnLY985hEsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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