SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5dd332b013cbaa83f5d788d9cba7da38a95df13340f27a52a892c1f3a7737a7c' 
  AND token = 's4MCeLB8fyCSrYhGXB/OI+I7FctwhTtNyPlJHD6EOjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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