SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17141c964889f5f9cb0929651e0b19507a3499630203d89743e6eff9a4d294dc' 
  AND token = 'vjDdn2WCwmDgoCidQV3qOaXdYoOmOyd4hASCCt0zB34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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