SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '930b179b39814873bc8097329d1b00cca0077a28741f3e5237631964bbc0302a' 
  AND token = '6z4ZdOonTSjBLihPCjLwrV2xYsKK52ZBxio9m3l1HEc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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