SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e14633a8f4c23dcc0665b9ec28cabffdb7a5f2a722f6abd55ca7462b8852a043' 
  AND token = 'NGoaLlQGmZlRuUiyO6RXjGw+E1q/eEQbZEm4uzRHqk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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