SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e3d6d4b860cca45b497143a48f27ed815dde52857f22a1de596847722304284' 
  AND token = 'uzEnQWFZNAjsU3E8CiWbpn5Xid/K5OeHEb2Hn+DrKcQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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