SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2c183934355e90c752eb833b5d0c407d0771dfef4bec1be1e8e56872d3d27eb2' 
  AND token = 'WjNyvdEtBBnedenoU9j99O2UTqLvyVZH6V82gZDJ46U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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