SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e97d0b96d5044f3aa57c6fe695290da995118a1e32107bcd54f0ffafcb92037' 
  AND token = 'ttFSGOFkwgogO3RuRJ+I21677UAjb5wSDSbRr7Vcz7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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