SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd38d3aa58ec15367b9085a993f997a6ab0ba490924f51d0fd47323ee63d6d7dd' 
  AND token = '202h/eGbwygdQqDGirXfyxNCG5hd0DOcwH0w7YLF08U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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