SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5861345524f77c278647d44a264dc9aff9c76b65466ab85d2770b0948799a18f' 
  AND token = 't1jDzIVYlnzpl0xj3yAKX/kjIw/NZecB5E2LIrTDUj0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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