SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '94f490a36266bfeed8cf492b94b89666712148fa40f464aad9ca9d08211a06f5' 
  AND token = 'xEJI2RFY118Oh131exLZVzc57KtzNz7RuWZbYOiRzGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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