SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a042209d3c9d0fd0707813380a62874cc639ecb1576190267107da51fe373cc8' 
  AND token = 'mL4C/wdAJKk/aQUnQaOEqtBKjotPUICR5dn5j9gDTa4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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