SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1db60e81f95374cf56f994fcbba3d0232236a584033ddb40ea76ba74b4d4c17e' 
  AND token = 'lx7vBO6SZ79h75CQYKFTgXZa0ZpTkFvgplGaSv/tHSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}