SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f08c34d2916fb853c05c326b652975971a451a2c7349bcd039fd18ca5c768352' 
  AND token = 'pdrshMVSPWV2Zf/AS1lfqA/VxsFwJv782dAO8CmgNjU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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