SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7097de1711aff61cd0301fe7c348b37a3ea5370772da4cd9e7eeb71ea2c8d8c' 
  AND token = 'BM7fSlplp9mEZGb/2w6k84g7zObtZ3OGI/KhIYolbpQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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