SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7f3598dc93006dfda5a01bba42b57811323a61986fe28c8d0b6814622d64dbb' 
  AND token = 'oBVm1s5ijUCcr/yPp4R4lSBnJ3iZgtMKvgAq1gD3C9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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