SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31954ad304e956bf158b4f2492d06b3a2084062399169da0c57c2e14c836dbb7' 
  AND token = 'vi3S9tYi7PukgPcOUjh/MdRwMb9p86kT8RPLeV05mTs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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