SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '39cfdd7d7687584593b53ae9d9aa766190f2bf0eac478c5dbd0b869e076bcb22' 
  AND token = 'mOMyvHncPClfDhxv4NsJq+dTzCMfmvhBVh6SecIX+4w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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