SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9c0de0036accaf6937c67fb4df49760c8d498dae33cedaa929d2de480f7838a' 
  AND token = 'yiaAYjPTs3mnf1uiXhlo6pziYieCYYSugySdCBI/hw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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