SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c56292a642c671c0d76f14f0427132bc2ddb12b4acb9fae27028c76a8846e21b' 
  AND token = 'txnJaSO6uPQpK0IMet/zN873SoCeURv4TjuQprpWFZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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