SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0db61d3bad6ec47662670fe85a55782d80f77f9ea9d9a12b7088e08aeef8850a' 
  AND token = 'gHamQ3fKytiZ1AySvJ9gPD2NXlG5KZHReCMHBXi0YZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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