SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8db01a5470416ab82aa5aa24560c88ae0327084f3d9ba2ff406d1adeeccf0d82' 
  AND token = 'ZooblOhdl07bvwFSDGy3pHafl1IYGZLdhyc3M2wBzpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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