SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49ee9188fafa8c09a2df21fcbd3ce333f42ec1cfc5db54d5f432564a62ac600b' 
  AND token = 'eLFWM2G2N6gEuQMtbcmZroDRP2ycz3dqdUnrGdio9UI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}