SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9b76918e067c0f42ba435f5e46a791b3aa087b76c0767b74b604d5d1ddc4c992' 
  AND token = 'GFNzv9M45DZKrXXbLQhMQGODnot11XjeTn6ECqTdCbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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