SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf1b020ca43b593eebe9e2ff269471b9569da6d9450a25769ec0403c4b993af6' 
  AND token = 'HQv+Kuc3DkjqgZjVgqHvkY/vo66MwjVz24mupUOfvug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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