SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03ae899a13c079ddae81e90f7d8ca05f35c908607e825cc598b8c62a7b4fb7fd' 
  AND token = 'QZVWW+gOOrjgzHghsFLch0LJQD18GW5ZkiwUG6JQHFs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}