SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '0db6a21dab61b5fb41a496cd574e4fa37e5544b884b5ec5f7c349b69b3851f92' 
  AND token = 'NPZeIHeeI7Vrt8fWi4RwsddzGTknOzx+f5hztT5vEvY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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