SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '692028a576a72b7adda167989207773c40340acbfac00dc163d574f351234861' 
  AND token = 'M89wLXQ0f9k3ldI1gtkYP9QA12uYDqB+Mx7Ml8HJSc0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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