SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e301cd8f3d490d6fbe731d9f755622805b5831489c34fe21b37236979eedcd7f' 
  AND token = 'N6PuOgtEXtQ+ZhfoZEMWe7+NyGpUNo5wUywnEWbrEAY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}