SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bc0fa9b8afc3b72fb30dcaeb07e16ac2a1838f9ae52f8452344db89361c8a8b' 
  AND token = 'h+YXTWulscqKcyEv4FwD94S45L9Ix9fpPCb3bRdmvB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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