SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '59305010def28384d7daed911988369fa342587ab6114a98b6764303408ff67e' 
  AND token = 'yJxglc61jx+DSqglpgSs/bseIPAmjVaD6wIX+AIVcT0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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