SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '746e177e3fb38cd665017b3af565a35559d5aedecdf1a51ae419c13168690594' 
  AND token = 'JfNpnnp+YSoen4rAqDno1Y+e/CRcPIqVu7BUS8Qac0k=' 
  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"
    }
  }
}