SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5ab9f7562d044658b99b15d4bbb4d4c6752c30d7cb575773f71a5bca24272e4f' 
  AND token = 'NaemiQsj6tX/dneUy9okWilzo8EJ75w70Nyvr9JnYRc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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