SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e03e4ac8aff4358072991dde5db67e1ab4f4e90b95cb22a5e131883f947fc2a7' 
  AND token = 'wB+e2Z/YXDnw5X6jqcx5XrGBg/GldRf9hlOIhKf1N/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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