SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdad5d34bdb7497f6bed24b7c8b0af038b129c1c854502d08da12ee9b11382f3' 
  AND token = 'wCnZUJLZ889vcAFSdCOLfhbSkj5iGeRyEf5FwC92+fc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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