SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '790e0f215bb90918efaf26d023cba1a86cbc653db80f40b01dc82dd78ef81ab9' 
  AND token = 'wBoChhY3wqmS0yxV24PdJjpGeebyot+JH+7/Yy9sT9Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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