SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7823cbf041143910cf57ac26390aa35bd04393033e43893b09ec545150d4023d' 
  AND token = 'F8SBfAkEmI9YZRwsuRX++2xKp6p5kHmHUibjcEhchn8=' 
  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"
    }
  }
}