SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2af523af51aef66fa7e99c7d48709c476f380219488cd47465086ef4bfdc0234' 
  AND token = 'QFKvQ7YuAOu09NAhMc8hkT2XpAcph/ycnQBzYSCJQhw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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