SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '038b55b2debaef708c5411267dbcfe610b3c4a328cdc58497b7a4dedadc19d5e' 
  AND token = 'AFZXQ+HUyjjvKhjCaQqrcQRBLqdbbNmWfB4SncbC+rg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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