SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9003a86587c2bab92faf00f77382c4c9d1df1e67f731e91b68c41432b8d79db6' 
  AND token = 'bGiKbSPr/iakAgBKC+XHpZE5PcbdVFYyFcVyV+xUHfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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