SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0d8052c730626642a7b7110c1b166d5ad3d3e2368a8cb2b2b40ca97b51323f16' 
  AND token = 'hkhZfJX9CRcQNNQAvPateqAiguqXZiFZMSw/NcGlHmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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