SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '30b8697bf0b4e5fbb57e44790a4893d33df34f0c561416568961796aebeb48c4' 
  AND token = 'FEBi1qAXVaAuKeASQ9mauQGY9FOKy3Q6c6rD6BUclsk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}