SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94aa41bfc317e83798e9ce88807d190e3159dd51e65db6a0ab4e20ecfd8b732f' 
  AND token = 'tdSkT9SiVCdGRJocTTEJZ7nYIX2zfFF9C+jKMJwihwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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