SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7e92423ce510bf8bb1afde219b960a5692144a40a88a3b7f4db2b5647272d0a4' 
  AND token = 'gJFwj/v5ASXFQZ+8VhcsID17R9rYn/l2pSAC0Rl+UrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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