SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '56ce07a1e71fc748ec5c8722411ed497cff947e676c4c39000ffa232b994ea22' 
  AND token = 'DWpYI9IfkXfT82ipwSmk5xyKsq9evVrCtuzD47aEdAI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00100

JSON explain

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