SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2dda71b8b6297103f4d8f249ecad59ec7c4dd02a025e3099280d233034860541' 
  AND token = 'uWHgmSotCWgSZcJgJzbhhTf6GVOgEUBwpACUdrQhZHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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