SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4318c0a106689e7240b1fd8ef4c3ec08daa35ac9e5ddb2387e3d70665a2dbe1' 
  AND token = '7GPsNJl5l/T2e2mODpPFvoJ9rz4icBwEPU/hGLlQ4qw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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