SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70afe2e381941821a6df86573791027d392ccb12bd1c67e607f385ac4bd05b55' 
  AND token = 'KmqJ+sV9BlwNzxRqHx1QYR6BPzV3FKvsferQGg9i32M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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