SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6d5b68e976113ca3be6f4b3011177902c47af299bec04e16f38e679ea508289d' 
  AND token = '+CYRSqQUth8sM+kbETQfAH7/+jxYwrimwA4SF/DToio=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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