SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1842666526b98a55600c6b44c7ca830246d97284b007bcbbc6600f58f65655ad' 
  AND token = 'kx5GX65CyAqCpgtCNGHjBJY+mYXZk/InRkqAXsFiHDg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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