SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd9e84b26c96e06fe69dd4013f1fa4f1ed7668c03195d9bc967accef84aa15588' 
  AND token = 'Qyt7+QQpbmHiNYugCsDtMhV0GdF3GexliW2xAbWtLlQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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