SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '2197fa4d71b0ba70eb400f661c35343048bd8b3471871703c1fc73501c8be7df' 
  AND token = 'fHLvKs9lOHEYqh40gpmokWwbjJh4DQlVr6yDyB/PZLw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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