SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f17bf180718bdefcfc885d641ee1e4fa7185f6b338469afefd0d71b2b196b8b9' 
  AND token = 'BGzHPJM1Jvf3yxJN8fBmFB1LN8FmMVUbc7G0p6jgJBI=' 
  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"
    }
  }
}