SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af6eb9fd5d28cee8f01dbc42ea7f12372a6b4125b2ed445a44282456dacec6e7' 
  AND token = 'yzEykheIGzF9U+MsXD8aElJgCD20BspTCxFZdfsgnJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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