SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf8709b37511218a088cdc95c3227210ede4370995801d5fa1ae470d8c0beca' 
  AND token = 'ksjWy15XLPKd+Yg3Rck0HxpQYIYSVV6zY8djqxsCuaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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