SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a10d9f45c22d43b6393b010fa82413371215cda310468444cd1bc261cbcedbbd' 
  AND token = '6m92/dvcl63T8218CcBzURe2Y93sdgnZ1w2vhWhnh04=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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