SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53da01a5e8c65d20862203d60784b6fab61b3fd180e88173aeb5bef8a4036508' 
  AND token = '30EvLbd7HwaibneU1ZCC/NGVMfsf06JUm6DrDTMv/mA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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