SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'beb046e2f15c378b6d19fbc38eba8e3533400b9affd8436057dc91ca07994f55' 
  AND token = 'pHwS0cClWnA7jFVgYsUU5tFtsMt/nXlSKJSxW5ZstGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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