SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '232bc9d4a973433b9317c5da18695eb0380907c3e2e87d95066d7bc3c5b08770' 
  AND token = 'D18ny0/+TngNtfeQdLavcfilxZKYkO1di1L6VwuyJ/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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