SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'a166fcbbb95a737f22f6906adb11d2463c4d973fb3370210e99be6c312e5d6a6' 
  AND token = 'GPGjM6qRa5DCJ+DIBGIx/8u0KJczXtvJZOkdH1F77rY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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