SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '40e964a27db2d065160e2a06b63db0d12e1998de565afd0a1613faab382e8b3a' 
  AND token = 'vpDc9r9M/2ZpQi/4jeR7wRvCbCVeGM24G3C8J1RYGgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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