SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b6060a662586773d3d42823fb6c0e68978d31387c72cfff12564275d41a580f' 
  AND token = '4KJTZCmbEgTyu/S4z+X3oNWukgA9o7e9K3GqVTQnSQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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