SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cc66d395f304e3dbacdfd7a0d069e7f5006edee0383f5aad1f13bed48c0930d' 
  AND token = 'KBoikE798Jxe12gY69fjFtmmnYWMA8q8YhBYpOvn2v8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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