SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b7c20e83f0eb463a1adafcccaa938b3dac6a4fd2588e4a342ab4c428adaa174' 
  AND token = 'eAY3O9EpkNO45YTQCUGlWZVsZ8YjsyIUET28Oi7jxfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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