SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8334d0a5ca7b65dcc14349ab3cec9b85243af7b7501fbf830c117f575d60b30e' 
  AND token = 'SMBh0OTEaRcLQZfDatGkMAAOH4mXxwSeKnu2pWvbHY4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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