SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2eca771e5a600ca78cad814b1e347c64748ff11ce10a7718759b5bf5b8e16206' 
  AND token = 'Gh/QN+0SiKEwsAfGAEnGyudJZTFnq1buLjYhLwmxQBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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