SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1213410523100271e16315d3d1738775a02b82df3cec968e714b40552c9fe70a' 
  AND token = 'Hyo8MYQ0ogpuefA0ouzqAvuYQSgtOKB5ks8lZXPvqMA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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