SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f99e7c7b0d4c36fbb3484c89e7156b836f74bc1903e7d92ac7dc2af160fc9617' 
  AND token = 'qh5LYi4O9chiqLOYfBk8nGJK+W7OKIILnlQOVLGiwNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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