SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '14033b58c2610131f7974fe84fc95387c50814946a4a0c8324c82350b9d95413' 
  AND token = 'RKxW2NQpXKJFtRxXPzmuya1Y3DAYBoDe6y2ZR4yJz2E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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