SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df5f249db040a77807f74e19d4baa73f617e5dc32fcef18fb78ec09598fbbd5e' 
  AND token = 'G5M9Ch2xZ3ewsc6TqlDzrx0zymr7DM+faFpZ0U+nHxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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