SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2ad72e5cbd168e92e8376e4356efc7c6086bbfaf52219adb8e48706a0fa3feb4' 
  AND token = 'gWPpSNTm3jpnIYoYuG0bsaT0Ywu6Vq34NvaIh8cSdiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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