SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f427d00fab180dd9652e4ffe642d63d562e08e4c4e74b72ee15a42285382cf8' 
  AND token = '1wcqThbDZYKUcPctrxlHHhy3pO3IxKzgvGKze1v9mL8=' 
  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"
    }
  }
}