SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '445525fc91759342d40d020934697075667197f30b4381483c65dcd74646dd0f' 
  AND token = 'ep4CzBS1myb7QpwxmWJZhTxdPdn8nkRm3xre183Zyvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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