SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7e28b7b477f72730946336f2cf354c4af2cc53b16ed064b94cfed7ca45eeb3d' 
  AND token = 'tSpGiAXHFBxb+Dl48r0pRu1hxd70m4rfjiagcb9iGL8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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