SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '63cbd02a68eb33ac23466306ccc867c5e5c9166ff2121ae4434c09002082618a' 
  AND token = 'RzGMr2Rc7bJ879pVIz45wGVcOtsK7jmiehggrCn62Ps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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