SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa7d93bf04981060a122dd8a0740e5cda35f471e22ff586e57e5d40b7acceb6b' 
  AND token = 'Zb8d/X0jKpNGDzH+LyTqNNIRseE1qmJYjwB/8St2Waw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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