SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5eb7492ef3e971ad963972b19f234f155ceca54c8efaf9d40bc5cfa92bb10c4b' 
  AND token = '/Jag16LOG0/4HvFfoorVQvqgBut/ESFxGkdgpq0RQpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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