SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f12705832295b185ef91a2c5e081f96b71646ef1c620aef2120ba3ab4ffb8e75' 
  AND token = 'tkDX/ju1yDkG/Z2LrXbtqSpCFQFBLvCFnD3XJH6hyY8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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